// GLOSSARY -- WEB3 INFRASTRUCTURE

What is Relayer?

1 min read Updated

A relayer is a service that submits transactions on behalf of users — enabling gasless transactions, meta-transactions, and cross-chain message delivery by paying gas fees and being reimbursed through other mechanisms.

WHY IT MATTERS

Relayers solve the gas UX problem. New users don't have ETH for gas. Cross-chain messages need someone to execute them on the destination chain. Account abstraction needs someone to submit UserOperations. Relayers handle this infrastructure.

In cross-chain protocols, relayers deliver messages from source to destination chain. In meta-transaction systems, relayers submit user-signed transactions and get reimbursed from the user's token balance or a paymaster.

Relayer infrastructure is a critical piece of the Web3 UX puzzle — making blockchain interactions feel as seamless as Web2 by abstracting away gas mechanics.

FREQUENTLY ASKED QUESTIONS

Do relayers have to be trusted?
Relayers submit transactions but don't control the content — the user's signature is already in the payload. A malicious relayer can delay but typically can't steal funds. Trust model depends on the specific protocol.
How do relayers make money?
Through fees: a percentage of the cross-chain transfer, a markup on gas costs, or payments from paymasters/protocols that want to sponsor user transactions.
What are gasless transactions?
Transactions where the end user pays zero gas. A relayer submits the transaction and a paymaster (sponsor) covers gas costs. The user might pay in other tokens or the dApp absorbs the cost.

FURTHER READING

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